[DocumentsUI module]Bump up the targetSdkVersion to 33

We need to ensure that all the mainline modules are targetting the
latest SDK version, hence bumping up the targetSdkVersion to the latest
i.e 33. Going forward this would be done by
default go/mainline-modules-target-sdk-version-fix.

Bug: b/211369649
Test: m DocumentsUI --skip-soong-tests;aapt2 dump badging ./out/target/product/vsoc_x86_64/system/priv-app/DocumentsUI/DocumentsUI.apk| grep targetSdkVersion:

Change-Id: Iae86f75323399f0c24c83e5ad1398fc3fbeb4fdb